Starting with the Anthropoid ape, who has a register of about 350 c.c., the Pithecanthropus about 900 c.c., and Neanderthal types registering as high as 1,620 c.c. of brain capacity, the best measures of the highest types of modern man show the brain capacity of 1,650 c.c. Specimens of the Cro-Magnon skulls show a brain capacity equal to that of modern man. There is a great variation in the brain capacity of the Neanderthal race as exhibited in specimens found in different centres of culture, ranging all the way from 1,296 c.c. to 1,620 c.c. Size is only one of several traits that determine brain power. Among others are the weight, convolutions, texture, and education. A small, compact brain may have more power than a larger brain relatively lighter. Also much depends upon the centres of development. The development of the frontal area, shown by the full forehead in connection with the distance above the ear (auditory meatus), in contrast with the development of the anterior lobes is indicative of power. It is interesting to note also that the progress of man as shown in the remnants of arts and industry corresponds in {30} development to the development of brain capacity, showing that the physical power of man kept pace with the mental development as exhibited in his mental power displayed in the arts and industries. The discoveries in recent times of the skeletons of prehistoric man in Europe, Africa, and America, and the increased collection of implements showing cultures are throwing new light on the science of man and indicating a continuous development from very primitive beginnings. _Progress Is Indicated by the Early Cultures_.--It is convenient to divide the early culture of man, based upon his development in art into the Paleolithic, or unpolished, and the Neolithic, or polished, Stone Ages.[2] The former is again divided into the Eolithic, Lower Paleolithic, and the Upper Paleolithic. In considering these divisions of relative time cultures, it must be remembered that the only way we have of measuring prehistoric time is through the geological method, based upon the Ice Ages and changes in the physical contour of the earth.